Air jet recorder



Deg. 6, 1938. F. 2-3. MARELLUQ 2,139,508

AIR JET RECORDER Filed Junel'T, 1956 Patented Dec. 6, 1938 "UNITEDSTATES AIR JET RECORDER Fredrick S. Marcellus, Scotia, N. Y., assignorto I General Electric Company, a corporation of New York ApplicationJune 17, 1936, Serial No. 85,723

1 Claim.

My invention relates to recording instruments and devices and has forits primary object the provision of sturdy, reliable apparatus forproducing a clear and legible record although placing only a relativelyvery light load on the moving element of the deflecting instrument ordevice used in connection with the recording apparatus.

ther and further objects and advantages will become apparent as thedescription proceeds.

In accordance with the invention in its preferred form, a sheet ofsuitable material forming a record chart is passed at any desired speedunder an air or vapor jet serving as a marking stylus. However, insteadof supplying marking material from the air jet, a marking member havinga surface coated with a suitable marking material is placed in closeproximity to the under surface of the record chart under the air jet andthe surface of the marking member is caused to travel at an appreciablevelocity with respect to the record sheet. The air jet serving as astylus blows the portion of the sheet under it against the markingmaterial, which is deposited upon the record sheet by abrasion andwithout placing any appreciable load upon the movable arm carrying theair jet. Owing to the relatively high velocity of the surface of themarking member, ample material may be deposited for producing a legiblerecord.

The invention may be understood morereadily from the following detaileddescription when considered in connection with the accompanying drawingand the features of the invention which are believed to be novel andpatentable will be pointed out in the claim appended hereto. In thedrawing, Fig. i represents in schematic form an end elevation includingthe essential elements forming an embodiment of my invention, and Fig.

2 is a reproduction of a sample record curve produced by the apparatusof Fig. 1 and illustrating its adaptability in representing rapidfluctuations and minute deviations in the value of a measured quantity.

Referring now more in detail to the drawing, a record chart or sheet Hin the form of a strip is represented coming from a supply roll, not

shown, and passing over guide rolls 12 to a reroll spool [3. The recordsheet H is preferably, but not necessarily, transparent or translucent.Although I prefer to utilize a record chart in the form of a strippassing from a supply spool to a reroll spool, it will be understoodthat my invention is not limited to this specific construction and thatit may be applied to any apparatusin which a chart in sheet form may beemployed,

whether the chart is arranged for longitudinal or circular travel. Thereroll spool I3 is provided with a shaft II, the projecting ends ofwhich engage leaf springs l5 which serve to hold the reroll spool i3against a driving-roll ll. The surface is of the record strip rolledupon the spool I3 engages the surface of a soft rubber face It of thedrive roll ll. The drive roll H is driven through a train of gears I! bymeans of a constantspeed motor 20, for example, a clockwork motor or asynchronous electric motor. I

A fine air nozzle 2| adapted to direct a fine stream of airor othersuitable gas including a vapor vertically against the sheet i I iscarried on the end of a transverse movable arm 22. The nozzle 2i issupplied with air through a tube 2i which may be carried by the movablearm 22 or may, itself, constitute a portion of the movable arm 22. Asoft rubber fiexible air hose 22 connected to a source of compressedairor other gas, not shown, is provided for furnishing the gas to the tube2|. The movable arm 22 is carried by the movable element of anindicating instrument or is connected to the movable element of anyother apparatus, the motion of which is to be recorded. Since suchapparatus forms no part of the present invention, I have indicated themovable element by showing only a portion of the movable arm 22. It willbe understood that, in the case of deflecting instruments, the flexibleair hose 22' is preferably supported near the pivot axis of the arm 22in order to prevent the air hose 22' from offering any resistance todefiection of the arm 22. A marking cylinder 23 is mounted below therecord strip H with its surface 24 in close proximity to the strip, sothat the air jet or the fine stream of air issuing from the nozzle 2iimpinges against the record strip ll, causing the portion thereof underthe tip of the air nozzle 2i to be wiped by the marking surface 23.

Although I have referred to a movable air nozzle, it will be understoodthat marking would take place in the same manner if the nozzle werefixed in position. Obviously, my invention embraces also apparatushaving a plurality of fixed or movable air nozzles for any desiredpurpose. For example, one or more stationary air nozzles 3| may be usedfor producing a base line 32 or division lines 33, thereby makingunnecessary the use of ruled record sheets or, if desired, one or moremarking points or styli, such as described in Patent No. 2,044,586granted June 16, 1936, on my copending application, Serial No. 656,131,filed February 10, 1933, and assigned to the same assignee as thepresent application, may be utilized in conjunction with the air nozzleii.

The marking member 24 may be of any suitable construction, for example,it may be composed of a substantially solid cylinder of graphite,and itssurface may comprise any suitable material, for example, the graphite atthe surface of such a cylinder. I have found that a sheet of carbonpaper 24 wrapped around a plain cylinder may satisfactorily be employed.The marking cylinder 23 is driven at a constant speed by means of aconstant-speed motor to which the cylinder 23 is connected by means of abelt 25 carried by pulleys 26 and 21 attached to the marking cylinder 23and the shaft of the motor 20, respectively. Satisfactory results havebeen obtained by causing the surface of the marking cylinder 23 totravel in the same direction as the record sheet II but at a greatervelocity. It will be understood, however, that, if desired, the surfaceof the cylinder 23 may be caused to travel in the reverse direction at avelocity greater or less than the velocity of the sheet II. It will beapparent that, where it is desired to insure ample legibility of therecord curve produced, such legibility may be enhanced by increasing thevelocity of the surface of the marking cylinder 23, thus increasing theamount of material deposited.

Since the motor 20 operates at a constant speed the surface of the softrubber face I! of the driving roll I i will travel at a constant speed.The surface of the soft rubber face l8 engages the surface of the outerlayer of the record strip wound on the reroll spool l3 and drives therecord strip H at constant speed, also thereby providing suitable timingof the record strip.

It will be observed from the drawing that the surface of the markingcylinder 23 is arranged to drive at a relatively higher velocity thanthe record strip H although I am not limited to any given range ofvelocities. I have found. for example, that suitable results may beobtained by giving the marking roll 23 a peripheral speed of about teninches per minute.

Although the air stream from the nozzle 2| may bear only lightly againstthe record strip ll, owing to the relative motion between the markingsurface 21 and the under surface of the record strip ll, sufficientmaterial is deposited upon the record strip II to form a clear record.The action is analogous to passing a pencil across a sheet of paper verylightly a'large number of times instead of only a single time withgreater pressure.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention together with theapparatus which I now consider to represent the best embodiment thereofbut I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

In apparatus for producing linear markings on a traveling sheet having amarking member supported on one side of a traveling sheet, a nozzlemounted in proximity to the marking member for directing a stream of gasagainst said sheet and pressing the portion of the sheet impinged bysaid gas stream lightly against the surface of the marking member.

FREDRICK S. MARCELLUS.

